Omar Mateen, the gunman who opened fire on a gay nightclub in Orlando and took hostages in a June attack that killed 49 people, was shot eight times by police and was not drunk at the time of the rampage, according to an autopsy report.

Omar Mateen, the gunman who opened fire on a gay nightclub in Orlando and took hostages in a June attack that killed 49 people, was shot eight times by police and was not drunk at the time of the rampage, according to an autopsy report.

While the bodies of Omar Mateen's victims were removed from Pulse nightclub overnight, investigators worked Monday to determine what motivated the Florida killer responsible for the worst mass shooting in U.S. history.

While the bodies of Omar Mateen's victims were removed from Pulse nightclub overnight, investigators worked Monday to determine what motivated the Florida killer responsible for the worst mass shooting in U.S. history.

The man responsible for the deadliest mass shooting in U.S. history was described by an ex-wife as emotionally unstable, had been interviewed by the FBI over potential terror links and pledged allegiance to the ISIS during a 911 call, sources say.

The man responsible for the deadliest mass shooting in U.S. history was described by an ex-wife as emotionally unstable, had been interviewed by the FBI over potential terror links and pledged allegiance to the ISIS during a 911 call, sources say.

(CNN) -- Federal authorities have arrested the wife of Pulse nightclub shooter Omar Mateen in connection with their investigation into the June mass shooting, FBI spokesman Prentice Danner said Monday.

Noor Salman faces federal charges, which were filed in the Middle District of Florida, including obstruction of justice and aiding and abetting Mateen's material support to ISIS, according to a law enforcement official.

The arrest was first reported by the New York Times.

Authorities believe Salman acted of her own free will and knowingly took steps to obstruct the investigation into the shooting, according to a law enforcement official.

The official said her claims that she was coerced through her husband's abusive behavior did not stand up.

Another official says the evidence will show that she was complicit and knew her husband was going to do something bad.

Attorneys for Salman have not responded to CNN's request for comment. CNN's Dan Simon visited her family's home in Rodeo, California, for reaction and was told "no comment."

"I am glad to see that Omar Mateen's wife has been charged with aiding her husband in the commission of the brutal attack on the Pulse nightclub," said Orlando Police Chief John Mina.

"Federal authorities have been working tirelessly on this case for more than seven months, and we are grateful that they have seen to it that some measure of justice will be served in this act of terror that has affected our community so deeply."

Salman was arrested in the San Francisco area Monday morning, Danner said. She will have a court appearance on Tuesday in Oakland, California, according to Assistant US Attorney Abraham Simmons.

Salman, who married Mateen in 2011, came under increasing scrutiny as authorities investigated Mateen, who killed 49 people and injured more than 50 others when he opened fire at Pulse, a gay nightclub in Orlando, Florida.

A law enforcement official told CNN last year that authorities were looking into whether Salman should face charges.

Orlando shooter texted wife during attack, source says

Salman gave conflicting accounts about what she knew of Mateen's intentions in the hours before the attack, authorities said last year.

Salman, who was Mateen's second wife, had been cooperating with various law enforcement agencies after the attack last June.

Months before the attack, Mateen added the name of his wife to his life insurance policy and made sure she had access to his bank accounts, two law enforcement officials said. The gunman transferred his share of the home in which his sister and brother-in-law lived to them for just $10. Mateen also bought his wife an expensive piece of jewelry, the sources said.

Salman told investigators that in the weeks leading up to the attack, Mateen spent thousands of dollars, buying among other things the guns used in the massacre. In April, he visited Disney World with his wife, and Disney security officials believe he was conducting surveillance, a law enforcement official told CNN.

Two days before the attack, he left his house angry and was carrying a bag of guns, his wife told investigators. Salman begged her husband not to leave and grabbed him by the arm, she said.

She told the FBI her husband said he wanted to carry out a jihadist attack, though she denied knowledge of his plans to launch the deadliest mass shooting in US history, a law enforcement official told CNN in June.

Two hours after the attack started, Mateen texted his wife at 4 a.m. and asked her whether she heard the news about the shooting. At one point, Salman told Mateen that she loved him.

FBI investigators initially didn't believe she was a co-conspirator in the attack but were looking into whether she should face charges for what information she may have had about Mateen's intentions, which she possibly failed to report to law enforcement.